Question: Express your answer in scientific notation. $5.4 \cdot 10^5 + 6.7 \cdot 10^4 = $
Solution: $\phantom{=} {5.4 \cdot 10^5} + 6.7 \cdot 10^4$ $={54 \cdot 10^{4}} + 6.7\cdot10^{4} $ $= (54+6.7)\cdot10^{4}$ $=60.7\cdot10^{4}$ $= 6.07\cdot10^{5}$